/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.catalina.core;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

import org.apache.catalina.Lifecycle;
import org.apache.catalina.LifecycleEvent;
import org.apache.catalina.LifecycleListener;
import org.apache.catalina.util.StringManager;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
import org.apache.tomcat.jni.Library;

/**
 * Implementation of <code>LifecycleListener</code> that will init and and
 * destroy APR.
 * 
 * @author Remy Maucherat
 * @author Filip Hanik
 * @version $Id: AprLifecycleListener.java 992432 2010-09-03 19:44:41Z mturk $
 * @since 4.1
 */

public class AprLifecycleListener implements LifecycleListener {

	private static Log log = LogFactory.getLog(AprLifecycleListener.class);

	private static boolean instanceCreated = false;
	/**
	 * The string manager for this package.
	 */
	protected static StringManager sm = StringManager
			.getManager(Constants.Package);

	// ---------------------------------------------- Constants

	protected static final int TCN_REQUIRED_MAJOR = 1;
	protected static final int TCN_REQUIRED_MINOR = 1;
	protected static final int TCN_REQUIRED_PATCH = 17;
	protected static final int TCN_RECOMMENDED_PV = 19;

	// ---------------------------------------------- Properties
	protected static String SSLEngine = "on"; // default on
	protected static String SSLRandomSeed = "builtin";
	protected static boolean sslInitialized = false;
	protected static boolean aprInitialized = false;
	protected static boolean sslAvailable = false;
	protected static boolean aprAvailable = false;

	public static boolean isAprAvailable() {
		// https://issues.apache.org/bugzilla/show_bug.cgi?id=48613
		if (instanceCreated)
			init();
		return aprAvailable;
	}

	public AprLifecycleListener() {
		instanceCreated = true;
	}

	// ---------------------------------------------- LifecycleListener Methods

	/**
	 * Primary entry point for startup and shutdown events.
	 * 
	 * @param event
	 *            The event that has occurred
	 */
	public void lifecycleEvent(LifecycleEvent event) {

		if (Lifecycle.INIT_EVENT.equals(event.getType())) {
			init();
			if (aprAvailable) {
				try {
					initializeSSL();
				} catch (Throwable t) {
					if (!log.isDebugEnabled()) {
						log.info(sm.getString("aprListener.sslInit"));
					} else {
						log.debug(sm.getString("aprListener.sslInit"), t);
					}
				}
			}
		} else if (Lifecycle.AFTER_STOP_EVENT.equals(event.getType())) {
			if (!aprAvailable) {
				return;
			}
			try {
				terminateAPR();
			} catch (Throwable t) {
				if (!log.isDebugEnabled()) {
					log.info(sm.getString("aprListener.aprDestroy"));
				} else {
					log.debug(sm.getString("aprListener.aprDestroy"), t);
				}
			}
		}

	}

	private static synchronized void terminateAPR()
			throws ClassNotFoundException, NoSuchMethodException,
			IllegalAccessException, InvocationTargetException {
		String methodName = "terminate";
		Method method = Class.forName("org.apache.tomcat.jni.Library")
				.getMethod(methodName, (Class[]) null);
		method.invoke(null, (Object[]) null);
	}

	private static void init() {
		int major = 0;
		int minor = 0;
		int patch = 0;
		int apver = 0;
		int rqver = TCN_REQUIRED_MAJOR * 1000 + TCN_REQUIRED_MINOR * 100
				+ TCN_REQUIRED_PATCH;
		int rcver = TCN_REQUIRED_MAJOR * 1000 + TCN_REQUIRED_MINOR * 100
				+ TCN_RECOMMENDED_PV;
		if (aprInitialized) {
			return;
		}
		aprInitialized = true;

		try {
			String methodName = "initialize";
			Class paramTypes[] = new Class[1];
			paramTypes[0] = String.class;
			Object paramValues[] = new Object[1];
			paramValues[0] = null;
			Class clazz = Class.forName("org.apache.tomcat.jni.Library");
			Method method = clazz.getMethod(methodName, paramTypes);
			method.invoke(null, paramValues);
			major = clazz.getField("TCN_MAJOR_VERSION").getInt(null);
			minor = clazz.getField("TCN_MINOR_VERSION").getInt(null);
			patch = clazz.getField("TCN_PATCH_VERSION").getInt(null);
			apver = major * 1000 + minor * 100 + patch;
		} catch (Throwable t) {
			if (!log.isDebugEnabled()) {
				log.info(sm.getString("aprListener.aprInit", System
						.getProperty("java.library.path")));
			} else {
				log.debug(sm.getString("aprListener.aprInit", System
						.getProperty("java.library.path")), t);
			}
			return;
		}
		if (apver < rqver) {
			log.error(sm.getString("aprListener.tcnInvalid", major + "."
					+ minor + "." + patch, TCN_REQUIRED_MAJOR + "."
					+ TCN_REQUIRED_MINOR + "." + TCN_REQUIRED_PATCH));
			try {
				// Terminate the APR in case the version
				// is below required.
				terminateAPR();
			} catch (Throwable t) {
				// Ignore
			}
			return;
		}
		if (apver < rcver) {
			if (!log.isDebugEnabled()) {
				log.info(sm.getString("aprListener.tcnVersion", major + "."
						+ minor + "." + patch, TCN_REQUIRED_MAJOR + "."
						+ TCN_REQUIRED_MINOR + "." + TCN_RECOMMENDED_PV));
			} else {
				log.debug(sm.getString("aprListener.tcnVersion", major + "."
						+ minor + "." + patch, TCN_REQUIRED_MAJOR + "."
						+ TCN_REQUIRED_MINOR + "." + TCN_RECOMMENDED_PV));
			}
		}
		if (!log.isDebugEnabled()) {
			log.info(sm.getString("aprListener.tcnValid", major + "." + minor
					+ "." + patch));
		} else {
			log.debug(sm.getString("aprListener.tcnValid", major + "." + minor
					+ "." + patch));
		}
		// Log APR flags
		log.info(sm.getString("aprListener.flags", Library.APR_HAVE_IPV6,
				Library.APR_HAS_SENDFILE, Library.APR_HAS_SO_ACCEPTFILTER,
				Library.APR_HAS_RANDOM));
		aprAvailable = true;
	}

	private static synchronized void initializeSSL()
			throws ClassNotFoundException, NoSuchMethodException,
			IllegalAccessException, InvocationTargetException {

		if ("off".equalsIgnoreCase(SSLEngine)) {
			return;
		}
		if (sslInitialized) {
			// only once per VM
			return;
		}
		sslInitialized = true;

		String methodName = "randSet";
		Class paramTypes[] = new Class[1];
		paramTypes[0] = String.class;
		Object paramValues[] = new Object[1];
		paramValues[0] = SSLRandomSeed;
		Class clazz = Class.forName("org.apache.tomcat.jni.SSL");
		Method method = clazz.getMethod(methodName, paramTypes);
		method.invoke(null, paramValues);

		methodName = "initialize";
		paramValues[0] = "on".equalsIgnoreCase(SSLEngine) ? null : SSLEngine;
		method = clazz.getMethod(methodName, paramTypes);
		method.invoke(null, paramValues);

		sslAvailable = true;
	}

	public String getSSLEngine() {
		return SSLEngine;
	}

	public void setSSLEngine(String SSLEngine) {
		this.SSLEngine = SSLEngine;
	}

	public String getSSLRandomSeed() {
		return SSLRandomSeed;
	}

	public void setSSLRandomSeed(String SSLRandomSeed) {
		this.SSLRandomSeed = SSLRandomSeed;
	}

}
